Redazione RHC : 11 August 2025 16:00
A recently discovered security flaw in the popular file compression software 7-Zip has raised considerable concern within the security community. All versions of 7-Zip prior to 25.01 are affected by this vulnerability, which results from improper handling of symbolic links during file extraction.
This vulnerability is CVE-2025-55188, discovered and reported by security researcher Landon on August 9, 2025, and allows attackers to perform arbitrary writes to files during archive extraction, potentially leading to code execution on vulnerable systems. When users extract a maliciously crafted archive containing unsafe symbolic links, 7-Zip follows these links during extraction, allowing attackers to write files to locations outside the intended extraction directory.
The vulnerability exploits 7-Zip’s symbolic link processing mechanism. According to the security advisory, the attack requires specific conditions to succeed. Once these conditions are met, attackers can create malicious archives containing symbolic links that point to sensitive system files. Once extracted, 7-Zip follows these symbolic links, allowing attackers to overwrite critical files such as SSH keys, .bashrc files, or other system configurations.
For Linux systems, attackers require the target to use a vulnerable version of 7-Zip when extracting an archive format that supports symbolic links, such as ZIP, TAR, 7Z, or RAR files. The exploitation process is simpler in Linux environments. On Windows systems, additional requirements must be met for effective exploitation. The 7-Zip extraction processmust have elevated privileges or operate in Windows Developer Mode to create symbolic links. This makes Windows systems less vulnerable, but not immune to attack.
Despite receiving a CVSS score of 2.7, classifying it as low severity, security experts warn that the practical impact could be much more significant. The vulnerability allows attackers to gain unauthorized access and execute code by targeting sensitive files that control system behavior. The vulnerability is particularly concerning because 7-Zip displays file paths before symlink resolution, allowing attackers to hide the true destination of their malicious writes.
7-Zip version 25.01, released on August 3, 2025, addresses this vulnerability with enhanced symlink handling. The update includes significant security improvements to prevent the creation of unsafe symlinks during archive extraction.
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